1. Field of the Invention
The present invention relates to a diffusion reaction method and a diffusion reaction device (diffusion reactor) and more particularly, it relates to a technology for forming fine particles using a diffusion reaction.
2. Description of the Related Art
As a method for producing inorganic fine particles or organic fine particles, there is a build-up method in which the fine particles are precipitated by making a solution prepared by dissolving fine particle forming materials into a solvent and a poor solvent into which the fine particle forming materials are hardly dissolved to contact each other.
As one example of the fine particles produced by build-up method, there are organic pigment fine particles contained in ink for an ink-jet device. In late years, output expression of images diversifies with development of digitalization and a temporal stability of dye image is demanded. Responding to such a movement, a method for forming a transparent dye image with favorable weatherability and favorable heat-resistance is required, and organic pigments attract attention in viewpoints of weatherability and heat resistance. In particular, employing organic pigment fine particles with diameters of 100 nm or shorter, preferably 40 nm or shorter is requested in late years.
Examples of the method for producing organic pigment fine particles in accordance with the build-up method include Japanese Patent Application Laid-Open No. 2004-43776. Japanese Patent Application Laid-Open No. 2004-43776 discloses that an aggregate of organic pigment fine particles is formed by, after preparing water based disperse liquid using a microreactor, making the water based disperse liquid to contact with acid (flocculant) each other in a tank, thereby enabling to easily remove floats (salt and an unnecessary dispersing agent) in the disperse liquid by a filter filtration, and then the organic pigment fine particles without any floats are produced by dispersing the aggregate again.